How to decide Main CI in De-duplication task in CMDB

[Asmita7]

Hi friends,

I am stuck across creating De-duplication template. I am not able to create condition for how to decide the Main CI?

1. Oldest created

2. Most recent discovered

3. More related items

4. Discovery source

5. Most relationships

6. Has asset

7. based on condition

Which approach to follow to select main CI ?

Please suggest.

Your help is valuable and appreciated.

Thank you

Asmi

[Tanushree Maiti]

Please refer this links, see if it helps you:

https://www.servicenow.com/community/cmdb-forum/de-duplication-template-option-to-make-last-newest-d...

[Preetha K]

Best Practice Order (Industry Standard)
Most implementations follow something like this:

1.Discovery Source (authoritative)
2. Has Asset
3. Most Relationships
4. More Related Items
5. Most Recent Discovered
6. Oldest Created (last fallback)

Main CI priority:

1. CI with Discovery Source = ServiceNow Discovery
2. If equal → CI with Asset
3. If equal → CI with most relationships
4. If equal → Most recently discovered
5. If equal → Oldest created

Avoid using only one condition. Use a priority stack of multiple rules so the system can always decide the correct CI.

[Selva Arun]

Hi Asmi,

Great question — deduplication templates can be tricky. Here’s a practical approach that’s worked well:

• Prioritize the Main CI in this order:

  1. Discovery source (e.g., ServiceNow Discovery) — most accurate, up-to-date attributes.

  2. Has asset — preserves financial/procurement context you can’t easily recreate.

  3. Most relationships — keeps established dependencies; relationships can be merged during dedup.

  4. Most recently discovered — use as a tiebreaker to reflect current state.

For the template conditions:

• Use Discovery Source as the primary condition.

• Add Has Asset as a secondary condition.

• Use Most Relationships as the tiebreaker.

• Enable relationship merging so no dependency data is lost.

This gives you a well-rounded, defensible setup that balances data accuracy, asset traceability, and relationship integrity.

Regards,

Selva ~Meena Arun

[shubhamseth]

@Asmita7 Good Question! 

Consider the below fields on CI to be as Main CI: 

1. Most Recent Discovery

2. Oldest Created

3. Has Most Relationship

4. Has Most Task associated 

5. Has Assets

If we get above on CI then should be consider as Main CI and action can be taken on left over CIs